Keep this one page instructional shortcut near your
sharpening area in your office for quick reference!
R A TIMELY APPROACH TO INSTRUMENT SHARPENING
| For Right Handers
SICKLE SCALERS & UNIVERSAL CURETTES
1. Position instrument vertically with blade
to be sharpened at the bottom.
6. Place surface of stone against right lateral
surface of the blade.
2. Stabilize entire length of instrument with
a firm grasp.
7. Tilt top of stone to 3 minutes after 12:00.
3. Brace upper terminal shank with your
thumb to counter-balance the pressure
of grinding the blade at the bottom.
4. Point tip or toe of blade toward you to
sharpen right cutting edge. Point tip or
toe away from you to sharpen opposite
cutting edge.
5. Keep terminal shank at 12:00.
8. Using continuous up and down motions,
move along the blade starting at the heel
third, middle third and finally the toe third.
9. To round the toe of curettes, direct the toe
toward 3:00.
10. Place the stone under the blade at 2:00.
11. Use continuous and overlapping up-anddown motions to “round” the toe.
GRACEY CURETTES
1. Position instrument vertically with blade
to be sharpened at the bottom.
2. Check the blade identification number:
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IT’S ABOUT TIME
A CLASSIC APPROACH TO
SHARPENING SCALERS & CURETTES
> Aim the toe of all ODD-numbered
Graceys toward you.
> Direct the toe of all EVEN-numbered
Graceys away from you.
3. Stabilize entire length of instrument
with a firm grasp.
4. Counterbalance the top shank with
your thumb.
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Telephone: 1-800-Hu-Friedy (1-773-975-6100) | Website: Hu-Friedy.com
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©2013 Hu-Friedy Mfg. Co., LLC. All rights reserved.
5. Tilt terminal shank to 3 minutes before 12:00.
6. Hold stone against right lateral surface and
tilt to 3 minutes past 12:00.
7. Using continuous up and down motions,
move along the blade starting at the heel
third, middle third and finally the toe third.
8. To round the toe of curettes, direct the toe
toward 3:00.
9. Place the stone under the blade at 2:00.
10. Use continuous and overlapping up-anddown motions to “round” the toe.
Keep this one page instructional shortcut near your
sharpening area in your office for quick reference!
IT’S ABOUT TIME
L A TIMELY APPROACH TO INSTRUMENT SHARPENING
A Classic Appoach to Sharpening Scalers & Curettes
| For Left Handers
This manual describes a classic approach to sharpening periodontal scalers and curettes.
Traditional sharpening techniques have relied upon “degrees of angulation” to achieve
the correct position of the stone in relation to the blade while sharpening. This alternative
method utilizes the simple visual imagery of the hands of the clock to establish the correct
positions while holding the instrument stationary and moving the stone.
SICKLE SCALERS & UNIVERSAL CURETTES
1. Position instrument vertically with blade
to be sharpened at the bottom.
6. Place side of stone against left lateral
surface.
2. Stabilize entire length of instrument with
a firm grasp.
7. Tilt top of stone toward to 3 minutes
before 12:00.
3. Brace upper terminal shank with your thumb
8. Using continuous up and down motions,
to counter-balance the pressure of grinding
the blade at the bottom.
4. Point tip or toe of blade toward you to
sharpen left cutting edge. Point the tip or
toe away from you to sharpen opposite
cutting edge.
5. Keep terminal shank at 12:00.
This manual is designed to be used independently or in combination with the DVD
“It’s About Time: A Classic Approach to Sharpening Scalers and Curettes.”
move along the blade starting at the heel
third, middle third and finally the toe third.
2. Check the blade identification number:
> Aim the toe of all EVEN-numbered
Graceys toward you.
> Direct the toe of all ODD-numbered
Graceys away from you.
3. Stabilize entire length of instrument
with a firm grasp.
4. Counterbalance the top shank with
your thumb.
WHEN TO SHARPEN
Repeated use of an instrument wears away minute particles of metal from the blade
causing the cutting edge to take on a rounded shape resulting in a dull, ineffective blade.
When the blade is dull, the clinician loses the ability to “feel” the sharp edge “grabbing”
onto a surface. Instead, the blade “slides” over the surface or deposit which causes
the clinician to use more lateral pressure and repetitive strokes in an effort to remove
deposits. This could result in burnishing rather than removing the deposit.
A DULL BLADE REFLECTS
LIGHT ALONG THE
CUTTING EDGE.
For best results, instruments should be sharpened lightly after each use rather than
reconditioning or recontouring after repeated use. Consistent sharpening on a regular
basis will conserve more of the blade as compared to grinding away an excessive
amount of metal when recontouring an extremely dull instrument.
9. To round the toe of curettes, direct the
toe toward 9:00.
10. Position the stone at 10:00.
11. Use continuous and overlapping up-anddown motions to “round” the toe.
LEARNING OBJECTIVES
Upon completion of this manual, the participant will be able to:
GRACEY CURETTES
1. Position instrument vertically with blade
to be sharpened at the bottom.
WHY SHARPEN
Instruments should be kept sharp and true to their original design. Dental procedures
are most effective when using sharp instruments because they reduce fatigue, improve
deposit removal, save time, enhance tactile sensitivity, and minimize patient discomfort.
5. Tilt terminal shank to 3 minutes past 12:00.
6. Hold stone against left lateral surface and
tilt to 3 minutes before 12:00.
7. Using continuous up and down motions,
move along the blade starting at the heel
third, middle third and finally the toe third.
1. List the benefits achieved when utilizing
scalers and curettes with sharp cutting
edges.
4. Describe how the traditional “degrees of
angulation” correspond with the clock
positions in this strategy.
2. Distinguish a “dull“ cutting edge from a
“sharp” edge.
5. Identify the essential grasp of both the
instrument and the sharpening stone as
defined in this technique.
3. Characterize the Arkansas Stone, the
India Stone, and the Ceramic Stone
according to:
8. To round the toe of curettes, direct the
toe toward 9:00.
9. Position the stone at 10:00.
a. Appearance
10. Use continuous and overlapping up-anddown motions to “round” the toe.
b. Coarseness or Grit variations
c. Preferred lubricant
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6. Describe the sharpening procedure
for Sickle Scalers, Universal Curettes,
and Gracey Curettes as outlined in this
technique.
7. Define the procedure for determining
when a “sharpened” cutting edge
actually is “sharp”.
HOW TO DETERMINE SHARPNESS
A hard acrylic test stick can be used to determine the sharpness of the blade. It is
designed specifically for this purpose. When the proper testing procedure is followed, a
sharp edge will bite into or “grab” the test stick and produce a metallic clicking sound. A
dull edge will slide over the surface of the test stick.
A SHARP CUTTING
EDGE DOES NOT
REFLECT LIGHT.
Another way to test the sharpness of an instrument is to inspect the blade visually.
Hold the instrument under a light (and if possible, under magnification) and rotate the
instrument until the edge is facing the light. A dull cutting edge will reflect light when it
has become rounded from use.
WHEN TO REPLACE INSTRUMENTS
Thoroughly inspect each blade after sharpening to determine if the original shape has
been significantly altered, or if the strength and integrity has been compromised.
©2012 Hu-Friedy Mfg. Co., LLC. All rights reserved.
1
2
SHARPENING STONES
Several types of sharpening stones are available for sharpening scalers and curettes.
Selecting the appropriate stone will make the sharpening procedure more efficient.
TYPE
Arkansas Stone
Ceramic Stone
India Stone
The Arkansas Stone is a natural stone with a fine grit. Oil lubrication
is recommended when using this stone. The oil serves as a vehicle to
float the metal particles as they are ground away from the blade and
prevents those shavings from becoming embedded in the stone. The
buildup of these shavings in the oil is referred to as “sludge.”
The Ceramic Stone is a synthetic stone available in either fine,
medium or coarse grits. Fine grit ceramic stones are excellent for
routine sharpening of dental instruments. Water can be used for
lubrication or the stone can be used dry. When sharpening with a
Ceramic Stone, there will be an accumulation of metal filings rather
than “sludge.”
The “I” Stone is a synthetic stone composed of aluminum oxide
crystals and is available in fine to coarse grits. Sharpening with an
India stone should always be followed by “finishing” the grinding with
a fine grit ceramic or Arkansas stone. Oil lubrication is recommended
when sharpening with this stone, however this stone can also be
lubricated with water or used dry.
SHAPES
3
Conical Stone
The conical stone is used for finishing or removing wire edges after
sharpening.
Cylindrical Stone
The cylindrical stone is used for finishing or removing wire edges
after sharpening.
Flat Stone
The flat stone typically is rectangular and is available in various
sizes. It can be an Arkansas, Ceramic or India Stone.
Wedge Stone
The wedge stone is a rectangular-shaped stone with rounded edges
and commonly is available as an Arkansas or India Stone.
STONE GRITS & LUBRICATION
There are many sharpening stone grits available. Be sure to use the proper grit for
sharpening dental instruments.
Coarse sharpening stones are intended mainly for recontouring and may be too
abrasive for light, regular sharpening as a coarse stone may remove more metal than
is necessary from the surface of the blade. If a coarser stone is used for recontouring
a blade, a finer grit stone should then be used to restore a keen cutting edge.
Arkansas Stones
India or I-Stones
Ceramic Stones
Fine
Grit
Medium
Coarse
Oil
Lubrication
Water
Dry
STONE CARE
After each use, stones should be wiped with a clean cloth or gauze to remove metal
particles. They can be scrubbed and/or ultrasonically cleaned to remove any lubricant
and metal shavings before sterilization. Alternate the areas used for sharpening to
prevent “grooving” in the stone.
4
YOUR WORK AREA
BASIC PRINCIPLES OF SHARPENING
Before beginning the sharpening process, assemble the required materials. In addition
to the instruments to be sharpened and the proper sharpening stones, you will need the
following items:
Safety Glasses: required when
sharpening, should cover the eyes
completely and have side panels
for maximum protection
Magnifying Glass or Loupes:
to view the blade
Gloves: should fit comfortably
Plastic or Acrylic Test Stick:
to test the cutting edge for
sharpness
Cotton Tipped Applicators: to
spread oil or water lubrication
Clock Diagram: to determine
the proper positioning of the
instrument, stone and test stick.
A clock image is provided in this
manual.
ANATOMY OF AN INSTRUMENT
For efficient sharpening it is important to be familiar with the anatomy of an instrument.
All scalers and curettes have three common components: the shank, working end & handle
TERMINAL SHANK: the area of the
instrument between the blade and the first
angle. This is the key feature for each scaler
or curette. Proper alignment of the terminal
shank will automatically place the blade in
the correct position for sharpening when
using the clock approach.
WORKING END: consists
of a blade that has one or
two cutting edges that run
from the terminal shank to
the tip or toe.
FUNCTIONAL SHANK: extends
from the handle to the blade and
includes the terminal shank.
Gauze: to wipe away sludge or
shavings from the surface of the
stone and the blade
5
6
GRACEY 1/2
TERMINAL
SHANK
SHARPENING OF THE SICKLE SCALER
CUTTING EDGE
FACE
INSTRUMENT LABELING
When the design name and number are stamped along the length of the handle, each working end
is identified by the number closest to it. If the design name and number are stamped around the
instrument handle, the first number identifies the working end at the top and the second number
identifies the working end at the bottom of the handle.
TIP
BACK
LATERAL
SURFACE
The sickle scaler has two cutting edges which are formed by the junction
of the facial surface with the two lateral
surfaces converging to a pointed
TERMINAL
SHANK
tip. This triangular cross-sectional results in an almost pointed back. The
CUTTING EDGE
facial surface of the blade is positioned at a 90° angle to the terminal shank.
FACE
This is important to note because
it affects
the positioning of the stone and
TIP
BLADE
instrument while sharpening.
GRACEY 1/2
TERMINAL
SHANK
BACK
LATERAL
SURFACE
G1/2
INSTRUMENT GRASP
Your grasp on the instrument is important throughout the
sharpening process. Hold the instrument in your nondominant
hand with a secure palm grasp. Brace your thumb against the
upper shank to counterbalance the pressure caused by grinding
the lower blade. Using the clock as a guide, hold the instrument
vertically with the blade to be sharpened at the bottom with the
tip toward you.
FACIAL
SURFACE
CUTTING
EDGE
TERMINAL
SHANK
CUTTING
EDGE
CUTTING EDGE
TERMINAL
SHANK
FACE
TIP
LATERAL
SURFACE
BLADE
BACK
LATERAL
SURFACE
FACIAL
SURFACE
CUTTING
CUTTING
When sharpening either
the
scaler you will restore
EDGE straight or curved sickle
EDGE
TERMINAL
the cutting edges
by grinding against the lateral surfaces of the blade and
SHANK
finishing the facial surface. Excessive sharpening of the facial surface is not
recommended because it will weaken the blade.
G1/2
STONE GRASP
Grasp the lower half of the stone in your dominant hand.
Hold the stone upright at 12:00 by placing your thumb on the
edge toward you and your fingers on the edge away from you.
This grasp stabilizes the stone and assists in maintaining a
consistent vertical motion. Move your entire arm in a fluid upand-down motion when sharpening.
LATERAL
SURFACE
BLADE
FACIAL
SURFACE
CUTTING
EDGE
CUTTING
EDGE
LATERAL
SURFACE
7
8
R
| For Right Handers
SHARPENING THE SICKLE SCALER
| For Left Handers
INSTRUMENT POSITION: Hold the instrument vertically in your nondominant hand. The
blade to be sharpened will be at the bottom with the tip pointed toward you. Brace the
top shank with your thumb and place your elbow directly in front of you on the table.
Position the terminal shank of the blade being sharpened at 12 o’clock.
INSTRUMENT POSITION: Hold the instrument vertically in your nondominant hand. The
blade to be sharpened will be at the bottom with the tip pointed toward you. Brace the
top shank with your thumb and place your elbow directly in front of you on the table.
Position the terminal shank of the blade being sharpened at 12 o’clock.
STONE POSITION: Place the lubricated side of the stone against the right lateral surface
of the blade. In an upright vertical position, initially direct the top of the stone upward
toward 12 o’clock and then tilt the top of the stone away from the instrument to 3 minutes
after 12 o’clock.
STONE POSITION: Place the lubricated side of the stone against the left lateral surface
of the blade. In an upright vertical position, initially direct the top of the stone upward
toward 12 o’clock and then tilt the top of the stone away from the instrument to 3
minutes before 12 o’clock.
INSTRUMENT POSITION
STONE MOVEMENT: Initiate grinding in a fluid up-and-down motion. Start at the heel
third of the blade and continue to the middle third and finally to the tip third. You should
see a buildup of sludge along the facial surface of the blade and stone. If you are using a
ceramic stone you will see a buildup of metal filings instead of sludge. Using gauze, wipe
the sludge or metal filings from the surface of the blade and the stone.
STONE MOVEMENT: Initiate grinding in a fluid up-and-down motion. Start at the heel
third of the blade and continue to the middle third and finally to the tip third. You should
see a buildup of sludge along the facial surface of the blade and stone. If you are using a
ceramic stone you will see a buildup of metal filings instead of sludge. Using gauze, wipe
the sludge or metal filings from the surface of the blade and the stone.
SHARPENING THE OPPOSITE CUTTING EDGE: Rotate the instrument so that the tip is
pointed away from you. Maintain the secure palm grasp and again brace the top shank
with your thumb. Position the terminal shank of the bottom blade at 12 o’clock. Tilt the
top of the stone slightly away from the handle to 3 minutes after 12 o’clock. Repeat the
grinding process maintaining the clock position. Using gauze, wipe the sludge or metal
filings from the surfaces of the blade and stone.
SHARPENING THE OPPOSITE CUTTING EDGE: Rotate the instrument so that the tip is
pointed away from you. Maintain the secure palm grasp and again brace the top shank
with your thumb. Position the terminal shank of the bottom blade upright at 12 o’clock.
Tilt the top of the stone slightly away from the handle to 3 minutes before 12 o’clock.
Repeat the grinding process maintaining the clock position. Using gauze, wipe the
sludge or metal filings from the surfaces of the blade and stone.
FINISHING
Curved Sickle Blade
With the tip of the blade
pointed toward you, hold
the terminal shank at 12
o’clock. Place the cylindrical
stone on the face of the
instrument with the stone
placed horizontally, at 3 and
9 o’clock. Lightly rotate the
cylindrical stone along the
face from the heel to the tip
to remove any wire edges.
9
L
SHARPENING THE SICKLE SCALER
STONE POSITION
INSTRUMENT POSITION
STONE POSITION
FINISHING
Straight Sickle Blade
With the tip of the blade
pointed toward you, hold
the terminal shank at 12
o’clock. Place a flat stone
horizontally on the facial
surface of the instrument
at the 3 and 9 o’clock
position. Move the stone
from side to side with light
pressure to remove any
wire edges.
Curved Sickle Blade
With the tip of the blade
pointed toward you hold the
terminal shank at 12 o’clock.
Place the cylindrical stone on
the face of the instrument
with the stone positioned
horizontally at 3 and 9
o’clock. Lightly rotate the
cylindrical stone along the
face from the heel to the tip
to remove any wire edges.
Straight Sickle Blade
With the tip of the blade
pointed toward you hold
the terminal shank at 12
o’clock. Place a flat stone
horizontally on the facial
surface of the instrument
at the 3 and 9 o’clock
position. Move the stone
from side to side with light
pressure to remove any
wire edges.
10
TERMINAL
SHANK
TESTING THE SHARPNESS OF THE
SICKLE SCALER BLADE
CUTTING EDGE
TOE
LATERAL
SURFACE
TEST STICK POSITION
To test the cutting edge, grasp the bottom third of the test stick in your non-dominant
hand between your thumb and index finger. Hold the test stick upright at 12 o’clock.
BACK
TERMINAL
The Universal Curette blade has two parallel cutting
edges that meet at a rounded
SHANK
toe. The cutting edges of the curette
are
formed
at
the
junction of the lateral
CUTTING EDGE
surfaces with the facial surface. The facial surface of the blade is positioned TERMINAL
to
SHANK
FACE
form a 90° angle with the terminalTOE
shank. This is important to note
because
it
90°
affects the positioning of the stone and instrument while sharpening.
INSTRUMENT POSITION FOR RIGHT-HANDERS
In your dominant hand, hold the instrument with a modified pen grasp. Position the
instrument handle behind the test stick with the tip of the blade pointed toward you.
Place the cutting edge to be tested against the left side of the test stick and fulcrum on
the right side of the test stick. Tilt the terminal shank slightly toward 3 minutes after
12 o’clock using the same angle that is used for scaling.
LATERAL
SURFACE
R
BLADE
BACK
INSTRUMENT POSITION
FOR RIGHT HANDERS
INSTRUMENT POSITION FOR LEFT-HANDERS
In your dominant hand, hold the instrument with a modified pen grasp. Position the
instrument handle behind the test stick with the tip of the blade pointed toward you.
Place the cutting edge to be tested against the right side of the test stick and fulcrum
on the left side of the test stick. Tilt the terminal shank slightly toward 3 minutes before
12 o’clock using the same angle that is used for scaling.
TESTING THE CUTTING EDGE
Press the cutting edge laterally into the test stick and release. Test the entire length
of the blade. A sharp edge will bite into or grab the test stick but will not slide over the
surface of the test stick. When a sharp cutting edge is released from the test stick, it
produces a metallic sound. If the cutting edge slides over the side of the test stick it may
indicate the blade is still dull, or the terminal shank is not positioned correctly. Vertical
shaving motions against the test stick will dull the cutting edge.
FACE
SHARPENING OF THE UNIVERSAL CURETTE
TERMINAL
SHANK
FACIAL
SURFACE
CUTTING
EDGE
CUTTING EDGE
TOE
LATERAL
SURFACE
L
FACE
90°
BACK
CUTTING
EDGE
TERMINAL
SHANK
BLADE
ROUNDED
UNDER
SURFACE
INSTRUMENT POSITION
FOR LEFT HANDERS
FACIAL
SURFACE
CUTTING
EDGE
90°
TESTING THE OPPOSITE CUTTING EDGE
To test the opposite cutting edge rotate the tip away from you positioning the
instrument handle in front of the test stick and repeat the same process as described
above. Be sure to test the entire length of the blade.
CUTTING
EDGE
TERMINAL
SHANK
BLADE
ROUNDED
UNDER
SURFACE
FACIAL
SURFACE
CUTTING
EDGE
11
CUTTING
EDGE
12
R SHARPENING THE UNIVERSAL CURETTE
| For Right Handers
INSTRUMENT POSITION: Hold the instrument vertically in your non-dominant hand.
The blade to be sharpened will be at the bottom with the toe pointed toward you. Brace
the side of the top shank with your thumb and place your elbow directly in front of you
on the table. Position the terminal shank at 12 o’clock.
13
L
SHARPENING THE UNIVERSAL CURETTE
INSTRUMENT POSITION
| For Left Handers
INSTRUMENT POSITION: Hold the instrument vertically in your non-dominant hand.
The blade to be sharpened will be at the bottom with the toe pointed toward you. Brace
the side of the top shank with your thumb and place your elbow directly in front of you
on the table. Position the terminal shank at 12 o’clock.
STONE POSITION: Place the lubricated side of the stone against the right lateral
surface of the blade. In an upright vertical position, initially direct the top of the stone
upward toward 12 o’clock and then tilt the top of the stone away from the instrument
to 3 minutes after 12 o’clock.
STONE POSITION: Place the lubricated side of the stone against the left lateral surface
of the blade. In an upright vertical position, initially direct the top of the stone upward
toward 12 o’clock and then tilt the top of the stone away from the instrument to 3
minutes before 12 o’clock.
STONE MOVEMENT: Initiate grinding in a fluid up-and-down motion. Start at the heel
third of the blade then continue to the middle third and finally the toe third. Remember
to maintain a continuous up-and-down motion using long strokes with moderate
pressure. You should see a buildup of sludge along the entire facial surface of the blade.
If you are using a ceramic stone you will see a buildup of metal filings instead of sludge.
Using gauze, wipe the sludge or metal filings from the surface of the blade and stone.
STONE MOVEMENT: Initiate grinding in a fluid up-and-down motion. Start at the heel
third of the blade then continue to the middle third and finally the toe third. Remember
to maintain a continuous up-and-down motion using long strokes with moderate
pressure. You should see a buildup of sludge along the entire facial surface of the blade.
If you are using a ceramic stone you will see a buildup of metal filings instead of sludge.
Using gauze, wipe the sludge or metal filings from the surface of the blade and stone.
STONE POSITION
SHARPENING THE OPPOSITE CUTTING EDGE: Rotate the instrument so that the toe
is pointed away from you. Maintain the secure palm grasp and again brace the top shank
with your thumb. Repeat the grinding process keeping the terminal shank at 12 o’clock
and the stone position at 3 minutes past 12 o’clock.
SHARPENING THE OPPOSITE CUTTING EDGE: Rotate the instrument so that the
toe is pointed away from you. Maintain the secure palm grasp and again brace the top
shank with your thumb. Repeat the grinding process keeping the terminal shank at
12 o’clock and the stone at 3 minutes before 12 o’clock.
ROUNDING THE TOE: To maintain the rounded shape of the curette toe, rotate the
instrument so that the toe of the blade is directed toward 3 o’clock. Position the stone
horizontally under the blade and tilt toward the 2 o’clock position. Move the stone in a
consistent up-and-down motion, overlapping the strokes and rotating around the toe to
maintain the rounded shape.
ROUNDING THE TOE: To maintain the rounded shape of the curette toe, rotate the
instrument so that the toe of the blade is pointing at 9 o’clock. Position the stone
horizontally under the blade directed at 9 o’clock and tilt upward toward the 10 o’clock
position. Move the stone in a consistent up-and-down motion, overlapping the strokes
and rotating around the toe to maintain the rounded shape.
SHARPENING THE OPPOSITE
CUTTING EDGE
FINISHING
FINISHING
Position the terminal shank at 12 o’clock with the toe pointed
toward you. Position the cylindrical stone horizontally across
the face of the blade at 3 and 9 o’clock. Lightly rotate the
stone along the face of the blade from the heel to the toe to
remove any wire edges.
Position the terminal shank at 12 o’clock with the toe
pointed toward you. Position the cylindrical stone
horizontally across the face of the blade at 3 and 9 o’clock.
Lightly rotate the stone along the face of the blade from
the heel to the toe to remove any wire edges.
Repeat the same sharpening process for the other end
of the instrument.
Repeat the same sharpening process for the other end
of the instrument.
FINISHING
ROUNDING THE TOE
FINISHING
INSTRUMENT POSITION
STONE POSITION
SHARPENING THE OPPOSITE
CUTTING EDGE
ROUNDING THE TOE
14
CUTTING EDGE
TOE
FACE
TESTING THE SHARPNESS OF THE
UNIVERSAL CURETTE BLADE
BACK
LATERAL
SURFACE
SHARPENING OF THE GRACEY CURETTE
TEST STICK POSITION
To test the cutting edge, grasp the bottom third of the test stick in your non-dominant
hand between your thumb and index finger. Position the test stick vertically upright at
12 o’clock.
CUTTING EDGE
The Gracey Curette differs from the Universal CuretteTOE
and Sickle Scaler as the facial
TERMINAL
SHANK
FACE
surface of the blade is tilted downward at a 70° angle to the terminal shank creating
only one functional edge to be sharpened, the lower edge. The cutting70°
edge on a Gracey
instrument is not curved to one side as itBACK
may seem but is straight as it comes forward
LATERAL
SURFACE when sharpening
off the terminal shank. This is important to remember
BLADEin order to
maintain the original blade design.
INSTRUMENT POSITION FOR RIGHT HANDERS
In your dominant hand, hold the instrument with a modified pen grasp. Place the
instrument handle behind the test stick with the toe of the blade pointed toward you.
Place the cutting edge to be tested against the left side of the test stick and fulcrum on
the right side. Tilt the terminal shank toward 3 minutes past 12 o’clock so that testing is
done at exactly the same angle that the blade is used for scaling.
INSTRUMENT POSITION FOR LEFT HANDERS
In your dominant hand, hold the instrument with a modified pen grasp. Place the
instrument handle behind the test stick with the toe of the blade pointed toward you.
Place the cutting edge to be tested against the right side of the test stick and fulcrum on
the left side. Tilt the terminal shank to 3 minutes before 12 o’clock so that testing is done
at exactly the same angle that the blade is used for scaling.
R
NON-FUNCTIONAL
EDGE
CUTTING EDGE
INSTRUMENT POSITION
FOR RIGHT HANDERS
FACIAL
SURFACE
TOE
FACE
TERMINAL
SHANK
70°
BACK
CUTTING
EDGE
LATERAL
SURFACE
BLADE
ROUNDED UNDER
SURFACE
TESTING THE CUTTING EDGE
Press the cutting edge laterally into the test stick and release. Test the entire length of the
blade. A sharp edge will bite into or grab the test stick but will not slide over the surface
of the test stick. When the edge is removed from the test stick, it produces a metallic
sound. If the cutting edge slides over the side of the test stick it may indicate the blade is
still dull, or the terminal shank is not positioned correctly. Vertical shaving strokes on the
test stick will dull the cutting edge.
L
The Gracey instruments are paired designs
and the blades are identified by a
NON-FUNCTIONAL
number. Each double-ended Gracey has an oddEDGE
and an even number which identifies
FACIAL
the blades. For
example, the Gracey 1/2
has the #1 blade on one end and the #2
TERMINAL
SURFACE
SHANK
blade on the opposite end.
INSTRUMENT POSITION
FOR LEFT HANDERS
70°
TESTING THE OPPOSITE CUTTING EDGE
To test the opposite cutting edge, rotate the toe away from you positioning the handle
and terminal shank in front of the test stick and repeat the same process. Be sure to test
the entire length of the blade.
BLADE
CUTTING
EDGE
GRACEY 1/2
ROUNDED UNDER
SURFACE
NON-FUNCTIONAL
EDGE
FACIAL
SURFACE
15
CUTTING
EDGE
16
R
SHARPENING THE ODD-NUMBERED
GRACEY CURETTE
R
| For Right Handers
BLADE POSITIONING: For all odd-numbered Gracey blades, point the toe of the blade
toward you when sharpening. This positions the lower cutting edge on the right side of
the blade, which is your dominant side and will make the sharpening task easier.
INSTRUMENT POSITION: Hold the instrument in your non-dominant hand vertically
with a firm palm grasp so that the blade to be sharpened will be at the bottom with the
toe pointed toward you. Focus only on the terminal shank of the instrument and tilt the
terminal shank toward 3 minutes before 12 o’clock. Remember to brace the top shank of
the instrument with your thumb.
SHARPENING THE EVEN-NUMBERED
GRACEY CURETTE
| For Right Handers
BLADE POSITIONING: For all even-numbered blades, point the toe of the blade away from
you. This positions the lower cutting edge on the right side of the blade, which is your
dominant side and will make sharpening task easier.
INSTRUMENT POSITION
INSTRUMENT POSITION: Hold the instrument in your non-dominant hand vertically with a
firm palm grasp so that the blade to be sharpened will be at the bottom with the toe pointed
away from you. Focus only on the terminal shank of the instrument and tilt the terminal
shank to 3 minutes before 12 o’clock. Remember to brace the top shank of the instrument
with your thumb.
STONE POSITION: Holding the stone in your dominant hand, position the stone against
the right lateral surface of the blade at 12 o’clock and then tilt the top of the stone
slightly toward 3 minutes past 12 o’clock.
STONE POSITION: Holding the stone in your dominant hand, position the stone against the
right lateral surface at 12 o’clock and then tilt the top of the stone slightly toward at 3 minutes
past 12 o’clock.
STONE MOVEMENT: Initiate sharpening in a fluid up-and-down motion starting at the
heel third of the blade then continuing to the middle third and finally the toe third.
Failing to sharpen the entire length of the blade is a common sharpening error. Be
sure to use a consistent movement along the entire blade. You should see a buildup of
sludge along the entire facial surface of the blade. If you are using a ceramic stone you
will see a buildup of metal filings instead of sludge.
STONE MOVEMENT: Initiate sharpening in a fluid up-and-down motion starting at the
heel third of the blade then continuing to the middle third and finally the toe third. Failing
to sharpen the entire length of the blade is a common sharpening error. Be sure to use a
consistent movement along the entire blade. You should see a buildup of sludge along the
entire facial surface of the blade. If you are using a ceramic stone you will see a buildup of
metal filings instead of sludge.
STONE POSITION
ROUNDING THE TOE: Maintain the terminal shank at 3 minutes before 12 o’clock.
Rotate the instrument so that the toe of the blade is directed at 3 o’clock. The face of
the instrument should be parallel to the table surface. Position the stone horizontally
under the blade at 3 and 9 o’clock and tilt the stone upward to the 2 o’clock position.
Move the stone in a consistent motion, overlapping the strokes and rotating around the
toe to maintain the rounded shape. Using gauze, wipe the sludge or metal filings from
the surface of the blade and stone.
17
STONE POSITION
ROUNDING THE TOE: Maintain the terminal shank at 3 minutes to 12 o’clock and rotate the
instrument so that the toe of the blade is directed at 3 o’clock. The face of the instrument
should be parallel to the table surface. Position the stone horizontally under the blade at
3 o’clock and tilt the stone upward to the 2 o’clock position. Move the stone in a consistent
motion, overlapping the strokes and rotating around the toe to maintain the rounded shape.
Wipe the sludge or metal filings from the surface of the blade and stone with the gauze.
ROUNDING THE TOE
ROUNDING THE TOE
FINISHING
FINISHING
Hold the terminal shank at 3 minutes before 12 o’clock with
the toe pointed toward you. Position the cylindrical stone
along the face of the instrument at 3 and 9 o’clock. Lightly
rotate the stone along the face from the heel to the toe to
remove any wire edges.
Hold the terminal shank at 3 minutes after 12 o’clock with the
toe pointed toward you. Position the cylindrical stone along
the face of the instrument at 3 and 9 o’clock. Lightly rotate
the stone along the face from the heel to the toe to remove
any wire edges.
FINISHING
INSTRUMENT POSITION
FINISHING
18
L
SHARPENING THE ODD-NUMBERED
GRACEY CURETTE
L
| For Left Handers
BLADE POSITION: For all odd-numbered Gracey blades, point the toe of the blade away
from you when sharpening. This positions the lower cutting edge on the left side of the
blade which is your dominant side and will make the sharpening task easier.
INSTRUMENT POSITION: Hold the instrument vertically in your nondominant hand
with a firm palm grasp so that the blade to be sharpened will be at the bottom with the
toe pointed away from you. Focus only on the terminal shank and position it slightly
toward 3 minutes after 12 o’clock. Remember to brace the top shank of the instrument
with your thumb.
SHARPENING THE EVEN-NUMBERED
GRACEY CURETTE
| For Left Handers
BLADE POSITION: For all even-numbered Gracey blades, point the toe of the blade
toward you when sharpening. This positions the lower cutting edge on the left side of
the blade which is your dominant side and will make the sharpening task easier.
INSTRUMENT POSITION
INSTRUMENT POSITION: Hold the instrument vertically in your nondominant hand
with a firm palm grasp so that the blade to be sharpened will be at the bottom with
the toe pointed toward you. Focus only on the terminal shank and position it slightly
toward 3 minutes after 12 o’clock. Remember to brace the top shank of the instrument
with your thumb.
STONE POSITION: Position the stone against the left lateral surface at 12 o’clock and
then tilt the top of the stone slightly toward 3 minutes before 12 o’clock.
STONE POSITION: Position the stone against the left lateral surface at 12 o’clock and
then tilt the top of the stone slightly toward 3 minutes before 12 o’clock.
STONE MOVEMENT: Initiate grinding in a fluid up-and-down motion starting at the heel
third of the blade then continuing to the middle third and finally the toe third. Failing to
sharpen the entire length of the blade is a common sharpening error. Be sure to use a
consistent movement along the entire blade. You should see a buildup of sludge along
the entire facial surface of the blade. If you are using a ceramic stone you will see a
buildup of metal filings instead of sludge.
STONE MOVEMENT: Initiate grinding in a fluid up-and-down motion starting at the
heel third of the blade then continuing to the middle third and finally the toe third.
Failing to sharpen the entire length of the blade is a common sharpening error. Be
sure to use a consistent movement along the entire blade. You should see a buildup of
sludge along the entire facial surface of the blade. If you are using a ceramic stone you
will see a buildup of metal filings instead of sludge.
STONE POSITION
ROUNDING THE TOE: Maintain the terminal shank at 3 minutes past 12 o’clock position
and rotate the instrument so that the toe of the blade is directed at 9 o’clock. The face
of the instrument should be parallel to the table surface. Position the stone horizontally
under the blade at 9 o’clock and tilt the stone upward to the 10 o’clock position. Move
the stone in a consistent motion, overlapping the strokes and rotating around the toe
to maintain the rounded shape. Using gauze, wipe the sludge or metal filings from the
surface of the blade and stone.
19
STONE POSITION
ROUNDING THE TOE: Maintain the terminal shank at 3 minutes past 12 o’clock
position. Rotate the instrument so that the toe is directed at 9 o’clock. The face of
the instrument should be parallel to the table surface. Position the stone horizontally
under the blade at 9 o’clock and tilt the stone upward to the 10 o’clock position. Move
the stone in a consistent motion, overlapping the strokes and rotating around the toe
to maintain the rounded shape. Wipe the sludge or metal filings from the surface of
the blade and stone with the gauze.
ROUNDING THE TOE
ROUNDING THE TOE
FINISHING
FINISHING
With the toe pointed toward you, hold the terminal shank
3 minutes before 12 o’clock. Position the cylindrical stone
horizontally across the face of the instrument at 3 and
9 o’clock. Lightly rotate the stone along the face from the
heel to the toe to remove any wire edges.
With the toe pointed toward you, hold the terminal shank
at 3 minutes past 12 o’clock. Position the cylindrical stone
horizontally across the face of the instrument at 3 and
9 o’clock. Lightly rotate the stone along the face from the
heel to the toe to remove any wire edges.
FINISHING
INSTRUMENT POSITION
FINISHING
20
TESTING THE SHARPNESS OF THE
GRACEY CURETTE BLADE
SHARPENING ANGLES
TEST STICK POSITION
Position both the test stick and the terminal shank of the Gracey instrument parallel to
each other at 12 o’clock.
The goal of instrument sharpening is to create a sharp blade while preserving the
ordinal shape of the instrument. Whether sharpening universal curettes, area-specific
curettes or sickles scalers the angle between the stone and the blade should always be
INSTRUMENT POSITION FOR RIGHT HANDERS
In your dominant hand, hold the instrument with a modified pen grasp. For oddnumbered Gracey blades, the toe will be pointed toward you. Bring the instrument
handle behind the test stick with the cutting edge to be tested against the left side of
the test stick and fulcrum on the right side. For even-numbered Gracey blades, the toe
will be directed away from you and you will bring the instrument handle in front of the
test stick. Hold both the terminal shank and the test stick at the 12:00 position. Be sure
not to place your ring finger on the top of the test stick. Instead, position your fulcrum
against the side of the test stick opposite the cutting edge to act as a fulcrum while
testing. Testing must be done at the same angle that the blade is used for scaling.
110º. The It’s About Time sharpening technique translates these degrees of angulation
to simple time positions on a clock face.
110˚
70˚
CHART OF ANGLES
R
INSTRUMENT POSITION
FOR RIGHT HANDERS
INSTRUMENT POSITION FOR LEFT HANDERS
In your dominant hand, hold the instrument with a modified pen grasp. For evennumbered Gracey blades, the toe will be directed toward you. Bring the instrument
handle behind the test stick with the cutting edge to be tested against the right side
of the test stick and fulcrum on the left side. For odd-numbered Gracey blades, the toe
will be pointed away from you and you will bring the instrument handle in front of the
test stick. Hold both the terminal shank and the test stick at the 12 o’clock position.
Be sure not to place your ring finger on the top of the test stick. Instead, place your
fulcrum against the side of the test stick opposite the cutting edge to act as a fulcrum
while testing. Testing must be done at exactly the same angle that the blade is used for
scaling, which is visually achieved when the terminal shank is parallel with the test stick.
135˚
L
TESTING THE CUTTING EDGE
Press the cutting edge laterally into the test stick and release. Test the entire length of
the blade. A sharp edge will bite into or grab the test stick. When the edge is removed it
produces a metallic sound. If the cutting edge slides over the surface of the test stick it
may indicate the blade is still dull or the terminal shank is not positioned correctly.
21
INSTRUMENT POSITION
FOR LEFT HANDERS
110˚
45˚
NOT ENOUGH
ANGULATION
70˚
TOO MUCH ANGULATION
CORRECT ANGULATION
When the internal angle is greater
than 80°, the blade becomes bulky
and is difficult to adapt to the tooth.
When the internal angle is less
than 70°, the blade becomes weak
and also dulls quickly.
When the stone is correctly placed
against the blade, the internal angle
of approximately 70° is maintained.
90˚
135˚
110˚
90˚
45˚
70˚
90˚
135˚
90˚
45˚
22
SHARPENING ANGLES
CLOCK FACE POSITIONS
GLOSSARY OF TERMS
SICKLE SCALERS &
UNIVERSAL CURETTES
• Terminal shank
at 12:00
• Terminal shank
at 12:00
• Top of stone at 3
minutes after 12:00
for right handers
• Top of stone at 3
minutes before 12:00
for left handers
L
R
Dominant/Non-dominant Hand: For right-handers, your
dominant hand is your right hand and nondominant is your
left hand. For left-handers, your dominant hand is your left
hand and nondominant is your right hand.
Fulcrum: The finger rest used to stabilize the dominant hand
during instrumentation or testing the blade for sharpness.
Modified Pen Grasp: The instrument is held with the thumb
and index finger placed on opposite sides of the handle. The
middle finger is placed on the shank to guide the movement of
the blade and the ring finger serves as the fulcrum.
GRACEY CURETTES
• Terminal shank
toward 3 minutes
before 12:00
• Top of stone at 3
minutes after 12:00
for right handers
R
Burnishing: To polish or smooth over a deposit instead of
removing it. This occurs during scaling with the use of dull
instruments.
L
• Terminal shank at 3
minutes after 12:00
Secure Palm Grasp: The instrument is held securely in
the palm of the hand with the thumb near the top of the
instrument to stabilize the instrument when sharpening.
• Top of stone at 3
minutes before 12:00
for left handers
Sludge: The accumulation of metal filings that becomes
suspended in the oil on the surface of the sharpening stone.
Terminal Shank: The section that extends between the blade
and the first angle (or bend) in the shank.
Wire Edge: A particle of metal that adheres to the cutting
edge after grinding.
23
24
SUGGESTED READINGS
Antonini, C.J., et al. Scanning EMS of Scalers. J.
Periodontol., 48(1), Jan. 1977.
Carranza, F.A., ed. Glickman’s Clinical Periodontology.
6th ed. Philadelphia: W.B. Sanders Co., 1984.
DeNucci, D.J., and Mader, C.L. Scanning Electron
Microscopic Evaluation of Several Resharpening
Techniques. J. Periodontol., 54(10), Oct. 1983.
Fedi, P.F. and Vernino, A.R. The Periodontic Syllabus.
3rd ed. Baltimore: Williams and Wilkins, 1995.
Grant, D.A., Stern, I.B., and Listgarten, M.A.
Periodontics. St. Louis: C.V.Mosby, 1988.
Pattison, A.M., and Pattison, G.L. Periodontal
Instrumentation. 2nd ed. Norwalk: Ct., Appleton and
Lange, 1992.
Perry, D.A., Beemsterboer, P., and Carranza, F.A.
Techniques and Theory of Periodontal Instrumentation.
Philadelphia: W.B. Sanders Co., 1980.
Sasse, J. Cutting Edges of Curets: Effects of Repeated
Sterilization. Dent. Hyg., 61, Jan. 1987.
Marquam, B.J. Strategies to Improve Sharpening. Dent.
Hyg., July/Aug. 1988.
Tal, H., et al. SEM Evaluation of Wear of Curets During
Standardized Root Planning. J. Periodontol., 56(9),
Sept. 1987.
Murray, G.H., Lubow, R.M., et al. The Effects of Two
Sharpening Methods on the Strength of a Periodontal
Scaling Instrument. J. Periodontol., 55(7), July 1984.
Wilkins, E.M. Clinical Practice of the Dental Hygienist.
7th ed. Philadelphia: Lea and Febiger, 1994.
Nield, G., and Snyder, N. An Edge On Success Videotape
Series. Univ. Of Texas, San Antonio, 1986.
Paquette, D.E., and Levin, M.P. The Sharpening
of Scaling Instruments: Part I–An Examination of
Principles. J. Periodontol., 48(3), March 1977.
25
Paquette, D.E., and Levin, M.P. The Sharpening of
Scaling Instruments: Part II–A Preferred Technique. J.
Periodontol., 48(3), March 1977.
Woodall, I. Comprehensive Dental Hygiene Care. 4th ed.
St. Louis: C.V. Mosby, 1993.
Zimmer, S. Instrument Sharpening–Sickle Scalers and
Curettes. Dent. Hyg., 52, Jan. 1978.
THE METHOD FOR SHARPENING PERIODONTAL SCALERS AND
CURETTES DESCRIBED IN THIS MANUAL IS BASED UPON A TEACHING
STRATEGY ORIGINALLY DESIGNED AND DEVELOPED BY:
Sherry Burns, R.D.H., M.S.
Hu-Friedy Mfg. Co., LLC. Global Educational Consultant
Author and Creator, It’s About Time
Former Associate Professor of Periodontics
University of Missouri-Kansas City, School of Dentistry
Burns, S., “Instrument Sharpening,” In Fedi, P.F. And Vernino, A.R. (Eds), The Periodontic Syllabus,
Baltimore: Williams and Wilkins, 1995